This invention relates to a valve timing control apparatus for an internal combustion engine which are configured to control an opening timing and a closing timing of, for example, an intake valve and an exhaust valve.
Japanese Patent Application Publication No. 2013-0136401 discloses a valve timing control apparatus for an internal combustion engine including a cover member which is provided on an front end side of a motor housing of an electric motor with a predetermined clearance to confront the front end side of the motor housing. A power feeding plate is fixed at a front end portion of the motor housing. A pair of inner and outer annular slip rings are fixed to the power feeding plate. The slip rings confront the clearance. Moreover, a pair of power feeding brushes are provided on a confronting inner surface of the cover member. The power feeding brushes are arranged to be slidably abutted on the slip rings, and thereby to feed the power to a coil of the electric motor.
A rotation sensing mechanism is provided between one end portion of a motor output shaft of the electric motor which is on the cover member's side, and the cover member confronting the one end portion of the motor output shaft of the electric motor in the axial direction. The rotation sensing mechanism is arranged to sense a rotation angle of the motor output shaft.
This rotation sensing mechanism includes a sensed portion fixed to one end portion of the motor output shaft; and a sensing portion provided to confront a tip end portion of the sensed portion of the cover member. This sensing portion confronts the tip end portion of the sensed portion with a predetermined gap.